Sound-reproducing disk for gramophones.



Ul?? SlATES- WTVZERLAND.

Specification or" Letters Patent. Application filed April 18,1905. Serial No. Zll).

'Patented July 3, 1965.

dish' luis each of its two .levee constructed as e spirall \'groo\'ed working surface in the forni ol a truncated cone.

A, first ohjeetiwhich is attained by this special formation oiC the disk-laces is to enable the dislq to be used on eac-h of its two laces, with tlieellect ofen ebling thereeeiving-stylus lo follow more easily the spiral grooves, owing to the inclination ol' the grooved parts, und at thesnine time to diminish the friction thereof,

because the deelivity or inclination of the grooved Working faces ot the disk aids SonieL what in the motion of the receiving-stylus. Another great advantage of this doublecone dis-li consists in that the latter has in its middle portion relatively great thickness,

that iti verysolid and resists well breaking and bending strains, during. its manipulation or under other influences.

ln the accompanying drawings, Figure l represents by way of example the preferred forni of the im )roved `disk in plan View, and Fig. 2 is an e evsition of the seine viewed edgewise,

In the construction shown the disk is pro- 'ided upon both laces with spiral grooves lor the. purpose ol renrcmlucing two aire, 'them laces being inclined to Vlorin emrli :L Worlii eurfeee in the l'orni oi u truncated cone. This inelinzitiiim o1 both the d' ecce is er waged in :umh :i manner that ne third-:nose yof the disk in its g ooved mrt dini'inielieri gritdueilj, Yl'roin the point .1.1y lo the periphery l), whereby the disk possesses in its middle ex-lion relatively great thivltnes lier lioth `Werl/ing faces of the disk the renrodueir g--Stylns will travel from the inner end el the epirol toits eurer end.

The disk of my invention is intended to he mounted upon a. stationery shalt which een.

only perform rotary motion around its geo-v metrie axis.

Yilhot .l claim is- An improved sound-reprodueing disk for grainophones, having each of its two lacet: constructed e spirzilly-grooved working surface in the lorin ol` si, truncated eolie,v the thickest portion el the disk being elthe cere ler sind the thickness diniinisnin toward the periphery, so es to provide. Strength and. stillness.

In Witness whereof il have hereunto signed my nzune, this -lth day ot' April, 1905` in the presence of two suheorihing wither es,

AVCHUJLFI iylATllE "With esses zV Gino. Ginrrlmn, AMAND BRAUN.

maximum 

